Electric detonator for use under high pressures



May 12,1925. 1,537,668

H. L. GRANT ELECTRIC DETONATOR FOR USE UNDER HIGH PRESSURES Filed D80. 24. 1924 nvcufoz HARRY I... GRANT9 Patented May 12,- was.

HARRY L. GRANT, or TAMAQUA, PENNSYLVANIA, ASSIGNOR T ATLAS POWDER COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

ELECTRIC lJETONATOR FOR USE UNDER HIGH PRESSURES.

Application filed December 24, 1924. Serial No. 757,847.

1 whom it may concern:

"it known that HARRY L., GR T, citif' -the United States, residing at 7' s'i aqua, in the county of Schuylkill and State of Pennsylvania, has invented certain useful Improvements in Electric l*)eto*nators for Use Under High Pressures,

of which the following is a specification.

This invention relates to a device for fir- ,ing expl'osives by electricity under extremely high pressures and has for its object to provide an improved device of the charac- -ter of those known as oil well detonators. The device of the present invention is adapted to be used as a general purpose detonator for firing explosives under great depths of water, oil or the like, andunder conditions where the pressure is very high.

Among' the objects of the invention is to provide a device of the character indicated,

characterized by simplicity in construction,

economy in manufacture, and reliability in operation.

An important object is to provide, in a device of the character'indicated, an assembly having great mechanical strength, thereby preventing injury to any part of the same while it is being transported or handled, previous to firing.

Eurt'her objects and advantages of the invention will be set forth in the detailed description which follows:

In the accompanying drawing:

Figure 1" is a plan view of the device of the present invention.

Figure 2 is a sectional viewupon line aa of Figure 1 showing the general method of assembly.

Like numerals designate corres onding parts in both of the figures of the rawing.

Referring to the drawing it will be seen that the 'detonator of the present invention comprises,.in the main, a shell 5, a pressure proof plug-5 and a ca 7. The shell 5 receives tlieiex'plosive c arge 8, said charge being referably in the form of a plurality of hol ow cylindersflo thereby leave a space within which, an electric detonator 9 is adapted to lie. .The lead wires 10 and 11 of the electricdetonator are united by soldering or other suitable means, indicated at 13 and 14, to the metallic conductors 15 and 16. These conductors are sealed in the plug 6 by a body of highly compressed powdered soapstone, indicated at 18 The packing dielectric.

constituted by the bod 18 is forced into the plug 6 under hydrau ic pressures of from 100,000 to 150,000 pounds per square inch. The capability of soapstone powder to densely pack,coupled with the very high pressures employed in forcing it into place withln the cap 6, results in the provision of a dielectric packing body 18 which will successfully resist the passage of the very high pressures encountered in oil wells of great depth.

The upper ends of the conductors 15 and 16 are united,either by soldering or by metallic sleeves 20, to the lead in wires 21 and 22, which pass through an opening 23, formed in the top of the ring 7. The space within the ring and above the dielectric body 18 is filled with a dielectric material such as phenol-resin or the like, indicated at 24 This material serves to hold the load In wires in their proper position and also serves'to' insulate them from each other and from the sides of the metal ring 7. This filhng also prevents external substances from coming in contact with the dielectric pack mg 18.

The pressure proof plug 6 is united with the shell 5 by means of a special thread 25,

which is illustrated and described in the prior Patent 1,516,009 of Nov. 18, 1924,

placed in the shell to hold the charge from moving or slipping in the shell, due to irregularities in size of the charge.

While I have found powdered soapstone to be highly efficient for use in the relation indicated it is to be understood that the in vention contemplates the use of an j suitable material having the capability of ecoming so hard and densely packed under hydraulic pressure, as to form a body capable of resisting the high pressures met with in deep wells, and which is, at the same time, Materials most efficient for this purpose are those having the characteristic soapy feel of soapstone, lard stone, pot stone and the like.

In the manufacture of oil well detonators I may prefer to use a medium tension fuse head instead of the ordinary low tension fuse head in the electric blastin cap 9. In this case I place only one metallic conductor 15 in the pressure plu 6, and employ the earth for the other 0011 uctor which is made possible by connecting one lead from the detonator 9, to the side wall of the shell 5 or pressure plug 6.

Having described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a device of the character described the combination with a casing carrying an explosive charge and detonating cap of a ressure resisting closure for said casing avin current conducting means passing theret rough, said current conducting means being sealed into said closure by a dielectric body consisting of a powdered material compressed therein under extremel high pressure, said casing being provided withan internal, substantially horizontally disposed grooved portion, into which some of said material 1s forced, to thereby interlock the dielectric material with the closure.

2. In a device of the character described the combination with a casing carrying an explosive charge and a detonating cap, of a pressure resisting closure having threaded engagement therewith, current conducting means passing through said closure and sealed into said closure by a dielectric bod compressed therein under extremely hig pressure, a ringlike element threaded upon 1,537;eos

closure for said casing having current conducting means passing therethrou h, said current conducting means being sea ed into said closure by a dielectric body consisting of a powdered material, compressed therein under extremely high pressure.

4. In a device ofthe character described, the combination with a shell, of a body of explosive material therein, a detonating cap therein, a pressure proof plug constituting a closure for the shell and current conducting means passing through the plug and connected to the detonating cap, said current conducting means being sealed in the plug by means of a body of dielectric material formed by compressing powdered soapstone, or analogous material, within the plug and about said current conductor, under very high pressure.

In testimony whereof he afiixes his signature in the presence of two witnesses.

. HARRY L. GRANT. Witnesses:

R. L. HILL, A. F. KRAIPF. 

